Ever need just a 1/2 can of cat food? Ever go crazy trying to invent a way to keep the remains sealed? Like me, you've probably done everything from foil to Pringles can tops. I've found that a well cleaned previous can will, of course, fit perfectly and firmly... just like when they are stacked on a shelf. Dogs parents: Let me know if it works with dog food cans, as well. It takes up a little more space but I have a feeling it will.